The present invention relates to an arm rest device for relieving load on parts of the human body when performing work by hand and wrist movements.
Such work by hand and wrist movements is carried out in connection with actuation of the joy stick or key of a control lever of vehicles, such as tractors, and buttons and keys of cash registers, terminals and the like apparatus.
The overloading of the muscles in shoulders and neck is a cause of the most usual occupational injuries. The risk is particularly great if the movements are small but at the same time require precision. The movements give rise to considerable stress in shoulders and neck. Equipment available today, such as adjustable arm rests which can be set in suitable positions, offer a certain amount of relief but are in no way sufficient except in certain very specific applications. The problem is often that the support does not follow all the movements performed. U.S. Pat. No. 1,706,634, German Pat. No. 452.585 and Swedish Pat. No. 403,700 represent this prior art. Another alternative is to suspend the forearm in a balance block, thus obtaining relief. However, the technique available today does not offer sufficient relief to the muscles affected.